Known hydroelectric generating equipment systems have mechanical drawbacks which substantially limit their economic utilization--particularly at low head sites. Particularly, all known types require a direct mechanical connection between the turbine and the generator. Known low-head axial turbine equipment are of three types: (1) The rim-generator type--in which the generator rotor is located on the periphery of the turbine runner; (2) the tube-type--in which the generator is located outside the water passage and connected to the turbine through an extended drive shaft; and (3) the bulb tubine type--in which both the runner and the generator are directly connected and enclosed within the water passage.
All three types require expensive complicated concrete Civil Works to encase and structurally support the turbine and generator in a common housing. There are also problems in matching up turbine speeds with generator speed requirements, accessibility for maintenance purposes to the important components and the inability to install most known equipment into most already existing dams or structures.
The following described invention proposes to solve all of the above problems and more, by allowing a physical separation of the turbine and the generator and accomplishing several other required features (such as synchronous generator speed control) through the unique application of certain fluid drive components.